Modern integrated circuits are made up of literally millions of active and/or passive devices such as transistors and capacitors. These devices are initially isolated from each other, but are later interconnected together to form functional circuits. Typical interconnect structures include lateral interconnections, such as metal lines (wirings), and vertical interconnections, such as vias and contacts. Interconnections are increasingly determining the limits of performance and the density of modern integrated circuits. On top of the interconnect structures, bumps are formed and exposed on the surface of the respective chip. Electrical connections are made through bumps to connect the chip to another element.